Class III's and malar prominence

[x]

The Class III male was found to have a larger malar prominence than the Class I male. The Class III female and the Class I female had similar prominence of the malar complex, but the anterior component of the Class III female‟s malar complex was more posteriorly positioned. The Class I male and female had similar size and position of the malar complex. The Class III male‟s malar complex was larger, positioned further laterally and elongated more anteriorly compared to the female Class III. Further, no difference in the shape the malar prominences was found.

Anyone else find this very surprising? I've always known class III's to have a depressed maxilla which extends up through the rest of the midface

[pekay]

isn't it case dependent?

[pekay]

what do you mean pekay?

The Class III male was found to have a larger malar prominence than the Class I male. The Class III female and the Class I female had similar prominence of the malar complex, but the anterior component of the Class III female‟s malar complex was more posteriorly positioned.

All singular, that article/journal is basically comparing starting points

[pekay]

58 Class I CBCT (26 male, 32 female) of Caucasian patients and 58 Class III CBCT (26 male, 32 female) of Caucasian patients age 12 to 18 years old were included in the sample. Horizontal and oblique slices were taken of the malar area from each CBCT. A pattern profile analysis was completed on each slice of both the hard and soft tissue malar prominences and measurements were made relating the analysis to the patient‟s midline and cranial base.

Ah ok

no pictures at all? not even if you pay for it?

[pekay]

do you want me to screen grab those or nah? no pictures of the kids in the study

that is what i wanted to see sucks

[Tiny]

Weird. Most class IIIs commonly have flat cheekbones.  Often class IIs have OK or good cheekbones.

However, there is an absolutely glaring issue in this study - the sample patients are 12-18 years old! That's not adult, especially for a man.   Most men's facial bones will keep growing til at least 18 or longer.  I'm not at all surprised that 12-18 year old class Is don't seem to have more malar prominence than 12-18 year old class IIIs as a lot of those class Is won't have even developed much in the way of cheekbones yet as they're a long way off adult bone structure

Is this a study done by medics or scientists?  Cos a lot of medics do really poor studies in terms of scientific rigor/common sense.  Good examples - when they feed herbivorous animals (mice) a high fat/protein diet and then say that the results means a omnivorous animal (human) should eat a low fat high carb diet etc etc. I could go on.  So much bad science in the world

Ex-scientist is saddened by bad science 

[Tiny]

They actually cover this in the article, and it's not what you expected:

"A more accurate representation of the differences in the malar complex between Class I and Class III individuals could be accomplished if this study were repeated with a larger sample and a sample where all of the participants had finished growing. The Class III malocclusion is due to multiple morphologies, but most involve some combination of a prognathic mandible and/or a retrusive maxilla. The prognathic mandible shows longer peak growth and increased post pubertal growth over the Class I mandible. Further, sexual dimorphism exists in the Class III patient population. The female Class III patient has smaller linear measurements, mandibular length, midfacial length, anterior cranial base length, upper face height and lower face height than males. One would predict based off of the growth characteristics and sexual dimorphism of Class III patients that with a larger sample size and an non-growing sample the differences reported in this study would be magnified."

Ok, so at least they admit that their study is essentially total bollocks.  If they know that class 3 skeletal characteristics aren't fully developed until late adolescence/early adulthood, why did they chose 12-18 year old sample patients??   


"The female Class III patient has smaller linear measurements, mandibular length, midfacial length, anterior cranial base length, upper face height and lower face height than males."
Doesn't this apply to all females, really?  Or at least partially?

[Tiny]

Do you actually have any evidence to support the study being "total bollocks"?  I mean you're coming across pretty strong with your convictions but you need to provide some sort of proof that the study was fallacious in any way. You can't just discount a study because you think it's "bad science" or it doesn't align with your view.

Also in the procedure they describe how it's done. Yes, there's a natural sexual dimorphism in skulls but they did the measurements on a scaled basis to account for these natural differences, and the malar projection relative to the rest of the cranium was how measurements were taken

"total bollocks" = really not terribly useful.  As in it's a 'no s**t sherlock' kind of a study. Maybe my British english is getting lost in translation. 

 I'm not trying to say that the study is intentionally misleading - it's not - or that I disagree with their view (such as there is, which isn't much).   If the study was claiming that class 3 adults had similar malar measurements to class 1s, then I would say that it's extremely fallacious.  What it's supposed to be trying to do is 'setting out to determine whether malar retrusion is real in class iii's or an illusion due to the retruded maxilla', it doesn't do very well at all as they chose sample patients whose age means the skeletal bones are not fully developed.  Which is why I gave it the "bollocks" label as it is impossible to achieve the objective of the study if you don't use adult patients with fully developed facial skeletons.  In that sense, it's bad science as they cannot possibly achieve their research objective using the sample that they chose.

It is a little misleading in that they're kindof implying that class 3s don't have malar decifiency.  Which you cannot say if your sample patients are 12-18.

 All this study really shows is that class 3 adolescent skulls don't show an appreciable malar deficiency compared to class 1s, which is the notable part of the study.  However, this isn't terribly surprising given the way that class 3 skeletal patterns tend to develop relative to age.  But this isn't really discussed in the comments, or doesn't seem to be, I didn't read the whole article.

I guess what we can surmise from this study is that assuming that class 3 skulls generally have less malar development, malar development seems to like upper jaw development in the class 3 patient - gets more obviously deficient in late adolescence and early adulthood.  If the point of the study was to see if malar development (or lack of) progresses in a similar way over time in the class 3 as maxillary development then it's an OK study (but would be better if they had both an adolescent and adult sample group so they could compare)

[Tiny]

I said "assuming" that class 3 skulls frequently have less malar development.  Which is generally what is observed, indeed I thought it was presumed typical of class 3.  I certainly can't recall seeing many class 3s with strong cheekbones, myself.  But lots and lots of flat cheekbones.  So at the moment I am going to make that assumption...

The study cannot claim that their results ("malar prominence in class 3 males") are continued/magnified into adulthood unless there is a decent paper showing that class 3 adult males have prominent malar bones.  Is there such a paper?  I'd be interested if there were we tend to see the exact opposite.  Otherwise I don't see how they can make this conclusion...it makes no sense to me 

Bone growth isn't done at 18 for a lot of males.  For women, yes, but for guys I think a lot have a little more to go especially in the regions affected by testosterone (e.g. chin point, bits of the jaw, brow ridge, malar bones...).  Which could be why we get the result that we do in this study and why for a fair number of guys their class 3, although present from a younger age, gets a lot worse between 14 and 21.

I consider the most interesting part of the study to be the fact that 12-18 year old class 3 males in this sample don't seem to show the typical malar hypoplasia that one usually sees in class 3s.  And if it was my study I would probably conclude it's something to do with testosterone, given that it seems that in class 3 men, malar prominence is normal (or even larger than normal) at 12-18 but often hypoplasic in adulthood, but in women you don't get that effect. Totally willing to be wrong if there is a study showing that this isn't statistically the case and that class 3s typically don't have malar hypoplasia/have hyperplasia instead.  But doesn't seem to be the case from what I've observed...

Do you agree that malar hypoplasia is typical/common for class 3s?  Or is this statistically untrue?  I'm just going on observations, haven't done any reading so if you have than I defer to that.

[pekay]

I still think it's case dependent, sure if you look hard enough you can find 30 Class III peeps with proper zygomatic/malar projection. What sort of point is this article/journal? trying to make?

[pekay]

I still don't know what this article is trying to say, is it that Class III people have better cheek-bone projection than Class I or II ?

[pekay]

more of this than class i:



anyway i'm utterly bored of arguing over this so I'll just have to leave it at a disagreement with celtic / pekay

oh ok I see it now, isn't that bad?

[pekay]

I dunno i guess it comes down to aesthetic preference, I've seen prominent cheekbones look good and bad

yes very true

isn't malar prominence basically buccal fat pad?